Mechanical calculators
My name is Kees Nagtegaal. I made this site for collectors of non-electric mechanical calculating devices.
My collection exists of over a hundred: 
Seidel & Naumann
- mechanical calculators (Odhner, Brunsviga, Facit),
- adders (Addiator, Produx, Resulta, etc.),
- adding machines (Comptometer, Burroughs, Plus, etc.),
- counters (Durant, Record, Hengstler, etc.),
- slide-rules (Aristo, Nestler,etc.),
- and more.
You can see all of those with description in the gallery. Feel free to check out my books and manuals, too.
A few calculators and most of my slide-rules are for sale. If you would like to purchase items, please ask. If you have any nice object (and a nice price) for my collection, please contact me. I am very interested in addiators and other slide-adders.
